Firms and organizations that use disk drive systems for the storage of information may have users in various geographic locations who need access to the data stored in the disk drive system. In order to preserve the data and permit its recovery in the event of system failure or a virus attack, such disk drive systems may generate snapshots of the system at user-defined time intervals. In the event of system failures, the data from shortly before the failure may be recovered through accessing the snapshot. Further, users at various geographic locations may also access such snapshots, either to recover data after a system failure or to access the system as configured at the time the snapshot was created.
In order to minimize the time required for remote users to access such snapshots, and to minimize the I/O load across the system, the system snapshots are often replicated at local sites for access by local users. Thus, a snapshot created may be replicated at any number of local sites and accessed there by local users. Such systems entail certain disadvantages however. For example, local users may have delayed access to a given snapshot because they will not be able to access the local snapshot until it is replicated at the local site. Such delays may similarly delay the recovery of data after a system failure. Further, replicating snapshots at numerous local sites from a single source creates significant I/O load on the source of the data, generally slowing the system.
Thus, there is a need in the art for a method and system to give local users faster access to snapshots, and to reduce the I/O load on the source of such snapshots resulting from the replication of such snapshots at numerous local sites.